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I have read that a .055 piston to head clearance is the minimum you should have. Is this not true?

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it is worth pondering the
"crevice volume"
effect

crevice volume is generally thought to be a bad thing
because it 'quenches' the flame and creates unburned hydrocarbons ... which reduces both power and fuel economy

there is crevice volume in the little gaps of the head gasket joint

there is crevice volume in the 'ring land' from the top of the first ring to the piston crown

could the undesired two crevice volumes
be combined
to eliminate a bit of both?

some engine builders try to do this
by having the piston come above the deck
enough to cover the head gasket joint
during the peak of the combustion event

it is an approach that might gain a bit of
power and fuel economy

in one of the last 'Engine Masters' competitions one of the top engines had a very large value for positive deck and this may have been one of his strategies

there is also a small effect in being able to use a tiny bit longer connecting rod

it is worth thinking about

another small detail

"The Devil is in the Details"

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I like that idea as you described it.mike

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an article on crevice volume

http://www.gofastnews.com/board/technica...ower-thief.html

for the hard core engine nuts

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Quote:

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an article on crevice volume

http://www.gofastnews.com/board/technica...ower-thief.html

for the hard core engine nuts

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